kentar

Understandable, but i've got fan heaters as backup and the immersion heater is taking care of the hot water. I'm pulling the trigger by the end of the month, which I think is ample time to decide on a plan.

My house is a 4 bed semi, early 1900's and is solid brick construction. Can't say how old the plumbing system is, but safe to assume pre 80's. An ASHP will be replacing the now defunct gas boiler and an unvented 200/250l hot water cylinder will also go in, but i'm unsure of what to do about the heating system. The current system uses a non-condensing boiler with a vented hot water cylinder. It lacks hot water pressure. The shower is fed using a pump to combat this but it runs the 140l tank dry within 10 mins. Half of the rads need replacing as they're extremely old. One rad is definitely full of sludge and barely gets warm even after a flush. The only saving grace is that all pipes to rads are 15mm. I've heard people claim that underfloor heating is best with ASHP, but also that it's difficult to retrofit to older properties. 1. Should I go for underfloor heating or radiators? 2. Can radiators be changed easily to underfloor heating at a later date, or does it need to be designed for it from the off? 3. Is there a third (or fourth) option? 4. Any other considerations?

That's an informative post, thanks.

Assuming all things being equal - size and configuration of tank, flow temp etc. (why would flow temp be different?) If i'm replacing a 20kw boiler, it would be fair to assume a 20kw ashp would heat the tank in a similar amount of time. However I only see people fitting ashp's with ratings in single digits. I've read that an oversized heat pump won't be as efficient due to it not being able to modulate down far enough and instead having to cycle on and off. The question is, why? They all run on inverters, in theory they should be able to go to near zero. Meanwhile a mid range Viessmann gas boiler will go down to 3kw, and the top end boiler will go down to 1.3kw. Yes, I will be upgrading the tank from 140l to 250l. However, were it to run out due to say several consecutive showers being required, I'd prefer that it was able to heat up as quickly as a gas boiler could. I know this can be mitigated somewhat by fitting a tank with a longer coil, but the same logic could be applied to a gas boiler. The central heating side isn't a concern for me. I know I can leave this on 24/7 and let weather comp do its thing. I'm neither for nor against ASHP's, i'm just trying to find a positive argument for installing one over a gas boiler. I know there may be some adjustment to be made, but if it causes more issues than it solves, then what actual reason is there for switching from a gas boiler? If it causes no extra hassle then i'm for it. And if it saves me money over installing a modern boiler that can modulate from 30kw-3kw then that's even better.

My requirement is that 4 people should be able to shower consecutively. My current hot water cylinder does not alllow for this and will be upsized. I can't however, fit a 500l cylinder. So I have make a reasoned decision and live with any shortcomings. Now my question is how long will a ASHP take to reheat a cylinder compared to a gas boiler? My opinion is that the gas boiler will do it quicker, based on the opinion of someone I know having one, and subsequently replacing it with a gas boiler due to it not heating water quickly enough. As I stated, I do not know the ins and outs of his installation. This is why I'm here, to gather further information from people who may be able to help me make an informed choice.

60c I believe. I'm not sure what the blend ratio of hot to cold is. I've got the mixer knob set so the temp I like is in the middle. The fact is, I can empty a 140l tank quite easily. It's pointless questioning or criticising how much water I use. I'm going to use it regardless.

A survey will be carried out to determine that, but none of what you have written concerns me.

Yes to a point, but you can't account for every eventuality. Fitting a 1000l tank in my airing cupboard 'just in case' is not viable. My current tank is 140l. I can drain that in less than 10 mins. Assuming 4 people need a shower, that's 560l. A tank that size is just not going to fit.

My boiler has died and I'm able to get a new ASHP installed via government grant. I have few concerns and i'd like some advice. My property is early 1900's solid wall construction. The loft has been insulated up to standard 10 years ago. New UPVC double glazing was fitted less than 5 years ago. The heating system is a mixture of new, old and really old. All pipe runs to the rads are 15mm, likely branching off a 22mm main (unverified). Firstly, everyone's telling me not to. Only one person I know has had one. I don't have any details about his system or installation, but he moved into a new house which had one and found it to be unsuitable because it was taking too long to heat the water after the DHW cylinder had emptied and meant having more than one consecutive shower was not possible. It was therefore replaced with a gas boiler. A couple of other concerns of mine are placement and noise. I'd prefer to mount mine high up on the wall against my house, as close as possible to the hot water cylinder on the first floor. This will be around 2m from my neighbours house. Is this possible? How noisy will it be? If it's not doable, can I have it placed at the end of the garden, around 20m away from the existing boiler? The boiler currently resides in the kitchen, with the hot water cylinder directly above it. Thirdly, heatgeek accredited installations are supposedly regarded as the best. How much of a risk is it using someone not accredited? Are there any other considerations? I'm not interested in saving a few hundred quid a year if it means that an ASHP causes more issues than it solves.

I'd like to install a garden room/workshop, roughly 4mx6m with a bifold door on the short side. I don't think I need any windows. Not sure what kind of roof style to go with just yet. I don't want to spend the next 6 months building it, so I was considering a pre fab and knocking it out within a couple of weeks. The trouble is I can't find what I want for what I deem is a reasonable price to performance. Everything I look at seems to be made of 3x2's, whereas I'd want 4x2's at a minimum. I've thought about buying a shed and then insulating it internally. Here's an example of something I was considering: https://www.nordictimberbuildings.com/product/20-x-10-pent-garden-summerhouse-with-bifold-doors/ £7400 is a ridiculous price considering something just slightly bigger, without aluminium windows and a bifold door is £3.5k. That's almost a £4k difference. I don't get it. https://www.nordictimberbuildings.com/product/20-x-12-apex-garden-shed-workshop/ I reckon I could build the first option myself with insulation and using 4x2's for £3k. Of course you can build it yourself for less you say... I don't mind paying a fair price, but I feel like i'm being robbed with what's on offer. As I said, I don't want to devote a great deal of time to building it myself. Which leaves me with having to buy one pre made, or having someone build one for me. I asked a chippie for a ballpark price and he came back with a figure of £10k. Again, I feel that's taking the piss. I've seen a lot of professional builds on youtube, and they don't take more than a couple of weeks - were talking fancy looking buildings here. I just want a notch above a basic shed. So then I looked at SIPs. I can't find the correct size on the website, but something half the size of what I want is around £3k. So roughly £6k for the shell and a couple of grand to finish it off. That would give me something substantially better than the first option, and I wouldn't have to faff about with spending more time insulating and boarding it. https://www.simplysips.co.uk/product/4-2m-x-3m-sips-kit/ £8k is more than I'd like to spend so I'm interested to hear your thoughts on this. What's my best option? Is there anything I haven't considered?